FIG. 1 illustrates screens of conventional telephone and calculator applications.
Referring to FIG. 1, a screen 10 of a telephone application may include a tap area 11 providing a menu for switching into a keypad, logs, favorites, or contacts screen, an area 13 where a dial number is displayed, and an area 15 where number keys 0 to 9 and function keys (e.g., *, #, a phone call key, a message key, a video communication key, a delete key, and the like) are displayed. A screen 20 of a calculator application may include a scroll area 21, an area 23 where calculation formula and result are displayed, and an area 25 where number keys and function (symbol) keys (e.g., operators (+, −, ÷, ×), parentheses, delete, calculation (=) key, and the like) are displayed.
As illustrated in FIG. 1, an application for a telephone function and an application for a calculation function all may include number keys and a delete key for deleting a mistyped number (or symbol) in common. However, since a conventional electronic device does not support compatibility between two functions, a user may find an application corresponding to each function to execute the found application. In other words, interfaces of a telephone application and a calculator application may be markedly similar to each other, but a calculation function using number buttons of the telephone application may not be supported.
Recently, electronic devices such as a smart phone, a tablet, and the like may basically include a telephone function and a calculator function. Furthermore, the electronic devices may provide a variety of services (applications) such as a social network service (SNS), search, map, public transportation, travel, weather, scheduling, music, video, and the like. A telephone function of functions that an electronic device provides may be used relatively frequently, but a calculation function thereof may not be frequently used. That is, many users do not tend to arrange a calculator application at an initial screen of a smart phone or a screen easy to find. Accordingly, it is inconvenient for a user to find a calculator application for simple calculation.